Hot electron distributions within the active region of quantum well lasers lead to gain suppression, reduced quantum efficiency, and increased diffusion capacitance, greater low-frequency roll-off and high-frequency c...
详细信息
We study the rate of intersubband electron transitions assisted by LO-phonon emission in type-II InAs/GaSb DQW heterostructure, which models the active region of antimonide-based intersubband cascade laser. We show th...
详细信息
We study the rate of intersubband electron transitions assisted by LO-phonon emission in type-II InAs/GaSb DQW heterostructure, which models the active region of antimonide-based intersubband cascade laser. We show that in type-II heterostructures with broken-gap band alignment the phonon-assisted process is the most favorable for the fast depopulation of the lower lasing states. The main peak of the electron-phonon resonance corresponds to electron transitions from the lowest electron-like subband to the top of the highest heavy-hole subband, which is spin-split and displaced from the center of the Brillouin zone due to the asymmetry of type-II InAs/GaSb DQW. We show that phonon-assisted depopulation can be conveniently employed even when the lower lasing level is designed near the upper edge of the heterostructure leaky window, where direct interband tunneling depopulation becomes, inefficient.
Quantization of electromagnetic field in isotropic dielectric medium occupying a half space is carried out. For a dielectric having a plane boundary with vacuum, we have constructed a complete orthonormal set of light...
详细信息
Quantization of electromagnetic field in isotropic dielectric medium occupying a half space is carried out. For a dielectric having a plane boundary with vacuum, we have constructed a complete orthonormal set of light waves propagating in a whole space. Using this set we calculated the rate of spontaneous emission of photons by electrons in quantum dots and quantum wells. We predict oscillations of photon emission rate as a function of the distance between a quantum nanostructure and the surface.
Reports a single-crystalline silicon (SCS) micromirror used for laser beam scanning in an endoscopic optical coherence tomography (OCT) system. The micromirror is fabricated by using a deep reactive-ion-etch (DRIE) po...
详细信息
ISBN:
(纸本)0780371852
Reports a single-crystalline silicon (SCS) micromirror used for laser beam scanning in an endoscopic optical coherence tomography (OCT) system. The micromirror is fabricated by using a deep reactive-ion-etch (DRIE) post-CMOS micromachining process. Thin bimorph actuation structures and movable bulk silicon structures are simultaneously achieved. The micromirror is 1 mm by 1 mm in size, coated with aluminum, and thermally actuated by an integrated polysilicon heater. The radius of curvature of the mirror surface is 50 cm. The mirror rotates 17/spl deg/ when a 15 mA current is applied. Cross-sectional images of 500 /spl times/ 1000 pixels covering an area of 2.9 mm by 2.8 mm are acquired at 5 frames/s by using an OCT system based on this micromirror.
Many radiological imaging scanners generate high-resolution three-dimensional (3D) images. For complex anatomical regions such as the lungs and heart, these images can be used for interactive navigation inside the ana...
详细信息
Many radiological imaging scanners generate high-resolution three-dimensional (3D) images. For complex anatomical regions such as the lungs and heart, these images can be used for interactive navigation inside the anatomy. The 3D image can act as a "virtual environment" representing the anatomy, and a computer-based system can be used for navigating through the environment. But such navigation must occur at interactive speeds if it is to be practical. This demands fast volume rendering from arbitrary viewpoints. The authors present an inexpensive fast volume rendering method that can generate sequences of views at interactive speeds. The method forms part of a system that permits dynamic navigation through 3D radiological images. The authors provide pictorial and numerical results for 3D pulmonary analysis.
We describe a GUI-based system called INTERSEG that can define 3D radiological image-segmentation processes. Using INTERSEG's GUI interface, the user first defines interactively some problem cues, which specify a ...
详细信息
This book constitutes the refereed proceedings of the International Symposium on Bioinformatics Research and Applications, ISBRA 2012, held in Dallas, Texas, USA, in May 2012.The 26 revised full papers presented toget...
详细信息
ISBN:
(数字)9783642301919
ISBN:
(纸本)9783642301902
This book constitutes the refereed proceedings of the International Symposium on Bioinformatics Research and Applications, ISBRA 2012, held in Dallas, Texas, USA, in May 2012.
The 26 revised full papers presented together with five invited talks were carefully reviewed and
selected from 66 submissions. The papers address issues on various aspects of bioinformatics and computational biology and their applications.
暂无评论